软件设计 石家庄铁道大学信息学院
实验13：享元模式
本次实验属于模仿型实验，通过本次实验学生将掌握以下内容：
1、理解享元模式的动机，掌握该模式的结构；
2、能够利用享元模式解决实际问题。
[实验任务一]：围棋
设计一个围棋软件，在系统中只存在一个白棋对象和一个黑棋对象，但是它们可以在棋盘的不同位置显示多次。
实验要求：
1. 提交类图；
2.提交源代码；
package 享元模式;
import java.util.*;
//坐标类:外部状态类
class Coordinates{
private int x;
private int y;
public Coordinates(int x,int y){
this.x=x;
this.y=y;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
}
//围棋棋子类:抽象享元类
abstract class IgoChessman{
public abstract String getColor();
public void locate(Coordinates coord){
System.out.println("棋子颜色:"+this.getColor()+",棋子位置:"+coord.getX()+","+coord.getY());
}
}
//黑色棋子类:具体享元类
class BlackIgoChessman extends IgoChessman{
public String getColor(){
return "黑色";
}
}
//白色棋子类:具体享元类
class WhiteIgoChessman extends IgoChessman{
public String getColor(){
return "白色";
}
}
//围棋棋子工厂类:享元工厂类
class IgoChessmanFactory{
private static IgoChessmanFactory instance = new IgoChessmanFactory();
private static Hashtable hashtable;
private IgoChessmanFactory(){
hashtable = new Hashtable();
IgoChessman black,white;
black = new BlackIgoChessman();
hashtable.put("b", black);
white = new WhiteIgoChessman();
hashtable.put("w",white);
}
public static IgoChessmanFactory getInstance(){
return instance;
}
public static IgoChessman getIgoChessman(String color){
return (IgoChessman) hashtable.get(color);
}
}
package 享元模式;
public class Client {
public static void main(String[] args) {
IgoChessman black1,black2,black3,white1,white2;
black1 = IgoChessmanFactory.getIgoChessman("b");
black2 = IgoChessmanFactory.getIgoChessman("b");
black3 = IgoChessmanFactory.getIgoChessman("b");
System.out.println("判断两颗黑棋是否相同:"+(black1==black2));
white1 = IgoChessmanFactory.getIgoChessman("w");
white2 = IgoChessmanFactory.getIgoChessman("w");
System.out.println("判断两颗白棋是否相同:"+(white1==white2));
black1.locate(new Coordinates(1,2));
black2.locate(new Coordinates(3,4));
black3.locate(new Coordinates(1,3));
white1.locate(new Coordinates(2,4));
white2.locate(new Coordinates(2,5));
}
}
3. 注意编程规范；
4.要求用简单工厂模式和单例模式实现享元工厂类的设计。